Question in-the

2.3 Systems Involving Nonlinear Equations - Line + parabola intersections
0:00

In the xy-plane, what is the y-coordinate of the point of intersection of the graphs of y equals, open parenthesis, x minus 1, close parenthesis, squared and y equals, 2 x minus 3 ?

Enter your answer:

In the xy -plane, what is the y -coordinate of the point of intersection of the

Hard-difficulty · SAT Math · Systems Involving Nonlinear Equations — Line + parabola intersections. Read the question above, select your answer, and check the full explanation below to understand exactly why the correct choice works.

Answer explanation

The correct answer is 1. The point of intersection of the graphs of the given equations is the solution to the system of the two equations. Since y equals, open parenthesis, x minus 1, close parenthesis, squared and y equals, 2 x minus 3, it follows that open parenthesis, x minus 1, close parenthesis, squared, equals, 2 x minus 3, or open parenthesis, x minus 1, close parenthesis, times, open parenthesis, x minus 1, close parenthesis, equals, 2 x minus 3. Applying the distributive property to the left-hand side of this equation yields x squared, minus 2 x, plus 1, equals, 2 x minus 3. Subtracting 2 x from and adding 3 to both sides of this equation yields x squared, minus 4 x, plus 4, equals 0. Factoring the left-hand side of this equation yields open parenthesis, x minus 2, close parenthesis, times, open parenthesis, x minus 2, close parenthesis, equals 0. By the zero product property, if open parenthesis, x minus 2, close parenthesis, times, open parenthesis, x minus 2, close parenthesis, equals 0, it follows that x minus 2, equals 0. Adding 2 to both sides of x minus 2, equals 0 yields x equals 2. Substituting 2 for x in either of the given equations yields y equals 1. For example, substituting 2 for x in the second given equation yields y equals, 2 times 2, minus 3, or y equals 1. Therefore, the point of intersection of the graphs of the given equations is the point with coordinates 2 comma 1. The y-coordinate of this point is 1.